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Dipolar hole-blocking layers for inverted perovskite solar cells: effects of aggregation and electron transport levels
摘要： Herein, we report on the synthesis and investigation of two triazino-isoquinoline tetrafluoroborate electrolytes as hole-blocking layers in methylammonium triiodide perovskite photovoltaic devices with fullerene electron extraction layer. We find that increasing the thickness of the dipolar hole-blocking layer results in a gradual increase in the open-circuit voltage suggesting that aggregation of the molecules can enhance the dipole induced by the layer. This finding is confirmed by theoretical calculations demonstrating that while both molecules exhibit a similar dipole moment in their isolated state, this dipole is significantly enhanced when they aggregate. Ultra-violet photoemission spectroscopy measurements show that both derivatives exhibit a high ionization potential of 7 eV, in agreement with their effective hole-blocking nature demonstrated by the devices. However, each of the molecules shows a different electron affinity due to the increased conjugation of one of the derivatives. While the change in electron transport level between the two derivatives is as high as 0.3 eV, the difference in the open-circuit voltage of both types of devices is negligible, suggesting that the electron transport level plays only a minor role in determining the open-circuit voltage of the device. Numerical device simulations confirm that the increase in built-in potential, arising from the high dipole of the electrolyte layer, compensates for the non-ideal energetic alignment of the charge transport levels, resulting in high open-circuit voltages for a range of electron transport levels. Our study demonstrates that the application of small molecule electrolytes as hole-blocking layer in inverted architecture perovskite solar cells is a powerful tool to enhance the open-circuit voltage and provides useful guidelines for designing future generations of such compounds.
关键词： open-circuit voltage,small molecule electrolytes,aggregation,device simulation,perovskite solar cells
更新于2025-09-16 10:30:52
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Barbier Hyperbranching Polymerization-Induced Emission toward Facile Fabrication of White LED and Light Harvesting Film
摘要： Luminescent polymers are generally constructed through polymerization of luminescent moieties. Polymerization itself however is mainly used for constructing polymer main chain and the importance of polymerization on luminescence has yet to be explored. Here, we demonstrate a polymerization-induced emission strategy producing luminescent polymers by introducing Barbier reaction to hyperbranching polymerization, which allows luminescent properties to be easily tuned from the traditional type to an aggregation-induced emission type by simply adjusting the monomer structure and the polymerization time. When rotation about the phenyl groups in hyperbranched polytriphenylmethanols (HPTPMs) is hindered, HPTPMs exhibit traditional emission property. When all phenyl groups of HPTPM are rotatable, i.e., p,p’,p’’-HPTPM, it exhibits interesting aggregation-induced emission property with tunable emission colors from blue to yellow, by just adjusting polymerization time. Further applications of aggregation-induced emission type luminescent polymers are illustrated by the facile fabrication of white LED and light harvesting film with an antenna effect greater than 14. This Barbier hyperbranching polymerization-induced emission provides a new strategy for the design of luminescent polymers, and expands the methodology and functionality library of both hyperbranching polymerization and luminescent polymers.
关键词： white LED,luminescent polymers,aggregation-induced emission,polymerization-induced emission,light harvesting film,Barbier hyperbranching polymerization
更新于2025-09-16 10:30:52
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Critical Role of Polymer Aggregation and Miscibility in Nonfullerenea??Based Organic Photovoltaics
摘要： Understanding the correlation between polymer aggregation, miscibility, and device performance is important to establish a set of chemistry design rules for donor polymers with nonfullerene acceptors (NFAs). Employing a donor polymer with strong temperature-dependent aggregation, namely PffBT4T-2OD [poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3″′-di(2-octyldodecyl)-2,2′;5′,2″;5″,2″′-quaterthiophen-5,5-diyl)], also known as PCE-11 as a base polymer, five copolymer derivatives having a different thiophene linker composition are blended with the common NFA O-IDTBR to investigate their photovoltaic performance. While the donor polymers have similar optoelectronic properties, it is found that the device power conversion efficiency changes drastically from 1.8% to 8.7% as a function of thiophene content in the donor polymer. Results of structural characterization show that polymer aggregation and miscibility with O-IDTBR are a strong function of the chemical composition, leading to different donor–acceptor blend morphology. Polymers having a strong tendency to aggregate are found to undergo fast aggregation prior to liquid–liquid phase separation and have a higher miscibility with NFA. These properties result in smaller mixed donor–acceptor domains, stronger PL quenching, and more efficient exciton dissociation in the resulting cells. This work indicates the importance of both polymer aggregation and donor–acceptor interaction on the formation of bulk heterojunctions in polymer:NFA blends.
关键词： nonfullerene acceptors,charge transport,morphology,charge generation,polymer aggregation
更新于2025-09-16 10:30:52
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Influence of Polymer Aggregation and Liquid Immiscibility on Morphology Tuning by Varying Composition in PffBT4Ta??2DT/Nonfullerene Organic Solar Cells
摘要： The temperature-dependent aggregation behavior of PffBT4T polymers used in organic solar cells plays a critical role in the formation of a favorable morphology in fullerene-based devices. However, there is little investigation into the impact of donor/acceptor ratio on morphology tuning, especially for nonfullerene acceptors (NFAs). Herein, the influence of composition on morphology is reported for blends of PffBT4T-2DT with two NFAs, O-IDTBR and O-IDFBR. The monotectic phase behavior inferred from differential scanning calorimetry provides qualitative insight into the interplay between solid–liquid and liquid–liquid demixing. Transient absorption spectroscopy suggests that geminate recombination dominates charge decay and that the decay rate is insensitive to composition, corroborated by negligible changes in open-circuit voltage. Exciton lifetimes are also insensitive to composition, which is attributed to the signal being dominated by acceptor excitons which are formed and decay in domains of similar size and purity irrespective of composition. A hierarchical morphology is observed, where the composition dependence of size scales and scattering intensity from resonant soft X-ray scattering (R-SoXS) is dominated by variations in volume fractions of polymer/polymer-rich domains. Results suggest an optimal morphology where polymer crystallite size and connectivity are balanced, ensuring a high probability of hole extraction via such domains.
关键词： PffBT4T-2DT,nonfullerene organic solar cells,liquid immiscibility,O-IDTBR,polymer aggregation,O-IDFBR,morphology tuning
更新于2025-09-16 10:30:52
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Rational Design of Axially Chiral Platinabinaphthalenes with Aggregation-Induced Emission for Red Circularly Polarized Phosphorescent Organic Light-Emitting Diodes
摘要： Circly polarized luminescent (CPL) materials have received great interest due to their potential applications in next-generation displays. However, the development of easily accessible red circularly polarized phosphorescent emitters for practical organic light-emitting diodes fabrication remains a grand challenge. In this paper, we report a new family of CPL-active platinum complexes based on the binaphthalene chiral platform. These axially chiral platinabinaphthalenes were facile synthesized by directly incorporating platinum(II) into the π-conjugated backbone of commercially available enantiopure binaphthalene derivate. These complexes exhibit aggregation-induced circularly polarized phosphorescence enhancement with high quantum yields up to 66% and luminescence dissymmetry factors around 2.6×10?3. Moreover, solution-processable circularly polarized organic light-emitting diodes (CPOLEDs) using these complexes as emitters show good performance with the maximum luminance up to 3500 cd m2 and dissymmetry factor values around 1.0×10?3. These findings by rational design of axially chiral platinabinaphthalenes are important for the development of high-performance CPL complexes for CPOLEDs.
关键词： circularly polarized luminescence,binaphthalene,organic light-emitting diode,platinum complex,aggregation-induced emission
更新于2025-09-16 10:30:52
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Nanococktail Based on AIEgens and Semiconducting Polymers: A Single Laser Excited Image-Guided Dual Photothermal Therapy
摘要： Semiconducting polymers (SPs)-based dual photothermal therapy (PTT) obtained better therapeutic effect than single PTT due to its higher photothermal conversion efficiency. However, most dual PTT need to use two lasers for heat generation, which brings about inconvenience and limitation to the experimental operations. Herein, we report the development of “nanococktail” nanomaterials (DTPR) with 808 nm-activated image-guided dual photothermal properties for optimized cancer therapy. Methods: In this work, we co-encapsulated AIEgens (TPA-BDTO, T) and SPs (PDPPP, P) by using maleimide terminated amphiphilic polymer (DSPE-PEG2000-Mal, D), then further conjugated the targeting ligands (RGD, R) through “click” reaction. Finally, such dual PTT nanococktail (termed as DTPR) was constructed. Results: Once DTPR upon irradiation with 808 nm laser, near-infrared fluorescence from T could be partially converted into thermal energy through fluorescence resonance energy transfer (FRET) between T and P, coupling with the original heat energy generated by the photothermal agent P itself, thus resulting in image-guided dual PTT. The photothermal conversion efficiency of DTPR reached 60.3% (dual PTT), much higher as compared to its inherent photothermal effect of only 31.5% (single PTT), which was further proved by the more severe photothermal ablation in vitro and in vivo upon 808 nm laser irradiation. Conclusion: Such smart “nanococktail” nanomaterials could be recognized as a promising photothermal nanotheranostics for image-guided cancer treatment.
关键词： semiconducting polymers,aggregation-induced emission fluorogens,fluorescence resonance energy transfer,A single laser,dual photothermal therapy
更新于2025-09-16 10:30:52
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Controlled assembly of AIEgens based on a super-quadruplex scaffold for detection of plasma membrane proteins
摘要： Quantification of plasma membrane proteins (PMPs) is crucial for understanding the fundamentals of cellular signaling systems and their related diseases. In this work, a super-quadruplex scaffold was designed to regulate assembly of oligonucleotide-grafted AIEgens for detection of PMPs. The nonfluorescence oligonucleotide-grafted AIEgen (Oligo-AIEgen) was firstly synthesized by attaching the AIEgen to 3′-terminus of the oligonucleotide through click chemistry. Meanwhile, the tetramolecular hairpin-conjugated super-quadruplex (THP-G4) as cleavage element and signal enhancement scaffold composited of three elements: a substrate sequence of DNAzyme in the loop region, partial hybridization region in the stem, and six guanine nucleotides to form G-quadruplex. Once the DNAzyme was anchored on the specific PMPs through aptamer-protein recognition, the substrate sequence on the loop of THP-G4 was cleaved by DNAzyme with the aid of cofactor MnII, resulting in the conformation switch of THP-G4 to the activated G-quadruplex scaffold. The latter could assemble Oligo-AIEgens to generate aggregation-induced emission (AIE) enhancement, resulting in a simple and sensitive strategy for detection of membrane proteins. Moreover, the DNAzyme continuously cut the next THP-G4 to achieve recycling amplification. Under the optimized conditions, this AIE-based strategy exhibited good linear relationship with the logarithm of MUC1 concentration from 0.01 to 10 μg mL-1 with the limit of detection down to 4.3 ng mL-1. The G4-assembled AIEgens provides a universal platform for detecting various biomolecules and a proof-of concept for AIE biosensing.
关键词： Biosensors,Fluorescence,DNAzyme,Aggregation-induced emission,DNA quadruplexes,Plasma membrane protein
更新于2025-09-16 10:30:52
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A novel σ-linkage to dianchor dyes for efficient dyes sensitized solar cells: 3-methyl-1,1-cyclohexane
摘要： We have synthesized two sensitizers based on the 3-methyl-1,1-cyclohexane, a novel σ-linkage to prepare dianchored dyes. These novel dyes are difunctionalized systems with aniline-donor (D), a π-conjugated spacer (π) based on thiophene or bithiophene and cyanoacetic acid as acceptor and anchoring group (A). The UV–vis absorption and the Differential Pulse Voltammetry have been used to study the effect of both σ-linkage and π-spacer. The relevant increase of the molar extinction coefficient of these dianchored dyes has been investigated by theoretical calculations. The dye bearing bithiophene results in a both broader and higher absorption as well as an adequate efficiency to transfer charge from D to A with respect to bithiophene dyes. The photovoltaic properties of these sensitizers without co-adsorbent have been studied. The novel difunctionalized derivatives present a relevant increase of the photocurrent density which results in a better performance with respect to the single dyes. The difunctionalized derivative based on bithiophene has given rise to an efficiency value of 7.8% and is stable up to 1000 h after the device assembly.
关键词： Aggregation,Metal-free sensitizer,Temporal stability,Multichromophore,Dye
更新于2025-09-16 10:30:52
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Comparing C60 and C70 as acceptor in organic solar cells: influence of the electronic structure and aggregation size on the photovoltaic characteristics
摘要： The difference in aggregation size of the C60 and C70 fullerenes affect the photovoltaic performance of devices assembled in the so-called bilayer architecture with poly[2,7-(9,9- dioctyl- dibenzosilole)- alt-4,7- bis(thiophen-2-yl)benzo- 2,1,3- thiadiazole] (PSiF-DBT) as the electron donor material. Despite the better performance of the C70 devices, which is related to the high absorption coefficient in the visible range and the superior charge transport properties, the short-circuit current variation upon annealing treatment at 100oC is approximately twice bigger when the C60 is the acceptor. We attribute this effect to the tendency of C60 in form smaller aggregate domains relatively to the C70. The increased roughness on the polymeric surface after annealing results in an enhanced donor/acceptor contact area and assists the fullerene diffusion deeper inside the polymeric layer. This effect leads to a better mixing between donor and acceptor species and create a interpenetrating layer close to the so-called bulk heterojunction. Since C60 forms smaller aggregates, this mechanism is more pronounced for this molecule. Therefore, a significant variation in the performance of the C60 devices is observed after this kind of treatment. Density Functional Theory calculations of the potential energy of interaction between two fullerene molecules and X-Ray measurements gives evidences to support this idea. In addition, combining spectrally resolved external quantum efficiency measurements with optical modeling our results also indicate the occurrence of the bilayer interfacial mixing for PSiF-DBT/C60.
关键词： Transfer matrix method,Density functional theory,Aggregation size,Fullerenes,Organic photovoltaics
更新于2025-09-16 10:30:52
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A Multi-Attribute Decision Making Process with Immediate Probabilistic Interactive Averaging Aggregation Operators of T-Spherical Fuzzy Sets and Its Application in the Selection of Solar Cells
摘要： The objective of this paper is to present new interactive averaging aggregation operators by assigning associate probabilities for T-spherical fuzzy sets (T-SFSs). T-SFS is a generalization of several existing theories such as intuitionistic fuzzy sets and picture fuzzy sets to handle imprecise information. Under such an environment, we developed a series of averaging interactive aggregation operators under the features that each element is represented with T-spherical fuzzy numbers. Various properties of the proposed operators are also investigated. Further, to rank the different T-SFSs, we exhibit the new score functions and state their some properties. To demonstrate the presented algorithm, a decision-making process algorithm is presented with T-SFS features. To save non-renewable resources and to the protect environment, the use of renewable resources is important. Solar energy is one of the best renewable energy resources and is also environment-friendly and thus the selection of solar cells is typically a multi-attribute decision-making problem. Therefore, the applicability of the developed algorithm is demonstrated with a numerical example in the selection of the solar cells and comparison of their performance with the several existing approaches.
关键词： t-spherical fuzzy sets,aggregation operators,multi-attribute decision making,interactive aggregation operators
更新于2025-09-12 10:27:22